MMP1 and interstitial lung disease: Three biomarkers were associated with ILD progression at 1-year follow-up: CXCL4 (odds ratio 2.67, 1.46–4.88; P = 0.001), MMP-1 (2.56, 1.43–4.59; P = 0.002) and ET-1 (2.18, 1.24–3.83; P = 0.007).